Sealer for wrapping machines



April lf', 193.5. A M. E. FORNSLER Y I 1,998,127

SEALER FOR WRAPPING MACHINES Filed March 15, 1934 FIG. l.

EXE

INVENTOR M f WM 1 TTORNEY Patented Apr. 16, 1935 AUNITI?. STE'I'ES PATENT OFFICE SEALER FR PPING MACHINES .Application March is, 1334, serial No. 715,745

Claims.

This invention relates to sealing devices for wrapping machines, especially such machines wherein the wrapping material such as waxed paper, Cellophane, etc., is sealed around the article by the application of heat.

In most heat sealing devices used heretofore, straight heater plates were employed which had the disadvantage of not touching' and therefore not sealing the entire seam of the package when the surface of the latter was of irregular shape like that of a loaf of bread or similar articles. Furthermore, it was found that some wrapping materials, especially cellophane, created a great deal of undesirable friction when heated, with the result that the package was injured or its seam was opened while passing the heater plates.

The main object of this invention is to produce a heat sealing device which can follow the contours of the advancing package and thereby assure perfect sealing of the package. Another object of this invention is to eliminate substantially all friction from the contact ci the heat sealing members against the package by employing a plurality of exible independently molmtedrollers which seal the seams of the package.

With these and other objects not specioally p thus heated by means of heating element lli, promentioned in view, the invention consists in certain constructions and combinations hereinafter fully described and then speclcally set forth in the claims hereunto appended.

In the accompanying drawing which forms a part o this 'specification and in which like char= acters of reference indicate the saine or like parts: Fig. l is a plan view ci the improved heat sealing device, consisting of end and bottoni Sealers;

Fig 2 is a sectional side elevation oi the e@ taken on line 2 2 of Fig. l;

Fig. 3 is a sectional side elevation oi the end Sealers, taken on line 3 3 of Fig. 2;

Fig. i is a sectional side elevation oi a modiiied form of bottom Sealers; and

Fig. 5 is a plan View of the same.

in carrying the invention into effect there is provided-a stationary heating element, a series of sealing elements having bores through which'sald' heating element passes loosely, and means for yieldingly pressing said sealing elements against said heating element, whereby said sealing elements are heated and yieldingly held in the path of a package so that they may accommodate themselvesto the contour of the package while heat sealing the package. In the best constructions contemplated the sealing elements may inplates. These various means and parts may be widely varied in construction for the particular device selected to illustrate the invention is but one oi' many possible concrete embodiments of thefsame. The invention, therefore, is not to be Vrestricted to the specic construction shown and described.

The improved sealing device comprises a, plurality of end sealing rollers i@ and bottom sealing rollers il. The rollers lo of the end sealers are stacked on top of each other axially in double tiers (Figs. 2 and 3) and are separated by ball bearings i2 to eliminate friction between rollers l0. 'lh'roughthe enlarged central bores i3 of the latter loosely passes a stationary electrical heating element lill the ends oi? which are supported in a housing iii. Rollers lil, which are ject partly out oi housing i5 into the path of the passing leal7 or package F to engage the ends 30 thereof. The rollers lil are always held under tension by series of yielding tension plates i6 carrying runners il which bear against rollers it, thus enabling each roller l@ to move freely with a minimum ofc friction. Plates it are supported in horizontal slots or vertical guide plates it atl tached to housing iti, and are equipped with tension springs l@ anchored to pins 2li held by housing i5. ils the package P is advanced yby means of arms 2i from between the end fold plates 22 40'/ (Fig. 2) past the stacks of end sealing rollers it, the latter roll smoothly over the end folds of the package, each heated roller itl following independently the contours oi the ends of the wrapped article, thereby assuring perfect end seals of the package. The arms 2l may be supported by a traveling endless chain (not shown).

The sealing rollers it ofsthe bottom sealer are arranged in a row projecting partly through the transversely slotted bottom plate 23 of the .50 wrapping machine. Fach roller il is yieldingly supported by means of a lever 2H having a saddie engaging loosely in c. circumferential groove 25 of the roller ii. Layers 24 are pivoted to a rod 28 supported in lugs 21 of plate 23. In 55 order that each roller ll may follow independently and firmly the contours of the bottom of the advancing package P, each lever 24 is equipped with a tension spring 28 anchored on a rod 29 held by lugs 30 of bottom plate 23. To lugs 30 is furthermore adjustably attached a slotted stop plate 3| which engages with levers 24 to check the upward movement of rollers Il. Through the enlarged central bores 32 of rollers il is passed a stationary electrical heating element 33 which provides rollers Il with suillcient heat for sealing the bottom seam of the advancing packages P. l

l In Figs. 4 and 5 is shown a modii'lcation of the bottom sealer in which the sealing rollers I I are replaced by a row of rings 34 through which is led a stationary electrical heating element 35. Each ring 34 is supported by means of pairs of rollers 36 pivoted to supporting arms 31 which are fulcrumed on rod 38 held in lugs 39 of bottom plate 23. To each arm 31 is attached a. weight 40 taking the place of the tension spring 28 in the embodiment shown in Fig. 2.

What is claimed is:

1. The combination with astationary heating element, of a series of sealing elements having bores through which said heating element passes loosely, and means for yieldingly pressing said sealing elements against lsaid heating element, whereby said sealing elements are heated 'and yieldingly held in the path of a. package so that they may accommodate themselves to the contour of the package while heat sealing the package.

2. 'I'he combination with a stationary heating element, of a series of sealing elements having bores through which said heating element passes loosely, and means for yieldingly pressing said sealing elements against said heating element, whereby said sealing elements are heated and yieldingly held in the path of a package so that they may accommodate themselves to the contour of the package while heat sealing the package, said sealing elements including sealing rollers provided with external circumferential grooves, and said means including spring-tensioned levers provided with saddles engaging in said grooves and pressing the rollers individually against said heating element.

3. The combination with a stationary heating element, of a series of sealing elements having bores through which said heating element passes loosely, and means for yieldingly pressing said sealing elements against said heating element, whereby said sealing elements are heated and yieldingly held in the path of a package so 'that they may accommodate themselves to the contour of the package While heat sealing the package, said sealing elements comprising rings, and said means provided with pairs of antifraction rollers engaging the peripheries of said rings and pressing 'them individually against said heating element.

4. The combination with a stationary heating element, of a series of sealing elements having bores through which said heating element passes v including counterweighted leverssealing elements against said heating element, whereby said sealing elements are heated and yieldingly heldin the path of a package so that they may accommodate themselves to the contour of the package while heat sealing the package, said sealing elements comprising sealing.

said heatingelement loosely passes, and springi tensioned levers provided with saddles engaging in said grooves and pressing said rollers individually upward through said slot and against said heating element, whereby said sealing rollers are heated and yieldably held in the path of packages along said bottom plate so that they may accommodate themselves to the contour of the bottom of the packages while heat sealing abottom seam thereof.

6. In a bottom sealer, the combination with a transversely slotted bottom plate adapted to support packages advanced Vthereover, of a stationary horizontal heating element, a series of rings through which said heating element loosely passes,

and counter-weighted levers provided with pairs of antifriction rollers engaging the peripheries of said rings and pressing them individually upward through said slot andy against said heating element, whereby said rings are heated and yieldingly held in the path of packages along said bottom plate so that the rings may accommodate themselves to the contour of the bottom of the packages while heat sealing a bottom seam thereof.

7. In an end sealer, the combination with a stationary housing having openings in one side thereof, of a stationary heating element vertically mounted in said housing, a stack of sealing rollers through which said heating element loosely passes, vertical guide plates mounted in said housing and provided with horizontal slots, a series of spring-tensioned plates mounted in said slots-and provided with runners bearing against the peripheries of said rollers to press them individually against said heating element and through the openings of said housing into the path of packages, whereby said rollers may ac` commodate themselves to the contour of a package end while heat sealing the same.

3. The combination with a runway for packages to be heat sealed, of a series of sealing rolls, and means for yieldingly and individually pressing said rolls into engagement with the surface of an article in said runway, said means including 1e- -vers having devices yieldingly urging said levers toward said runway, and means rotatably supporting said rolls on said levers, and means for 4heating the rolls.

'MAX E. FOERNSLER. 

